<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <ol id="elem">
      <li>Hello</li>
      <li>World</li>
    </ol>

    <script>
      const elem = document.getElementById("elem");
      // document.querySelectorAll()
      function clear(elem) {
        elem.innerHTML = "";
        // [...elem.querySelectorAll("li")].forEach((el) => {
        //   el.remove();
        // });
        // [...elem.children].forEach((el) => {
        //   el.remove();
        // });
      }
      clear(elem); // 清除列表
    </script>
  </body>
</html>
